Which isolating relays are recommended for the separation of the power supply signals (counting, HT / NT and measuring period)?
In addition, in the appendix to your information, I have attached to you the data sheet of an optical fiber isolating relay (the communication with the meter takes place serially via fiber optic cable, as already mentioned); This relay is widely used by many utilities (by EMH, please inquire about configuration). In cases where conventional isolating relays are still used, these are controlled by the meter via 100 V AC or 230 V AC signals. A common isolating relay would be the Deppe triple separation relay ZMT 80-01. The Siemens 7FR50 66 -... (58, 115, 230 V AC) Siemens relays you mentioned are still familiar to me (they are still around in our previous projects) and are suitable for any optimization system in terms of signal duration (at least 80 ms) but, as far as I know, they are almost not used anymore. The pulse detection of the U1500 is interrupt-controlled; the operating system interrupts the program execution every millisecond, so that even very high pulse frequencies and very short signal durations can be detected (thus all common isolating relays with MOSFET or relay outputs can be used with the U1500, the isolating relay usually specifies the energy provider, the installation takes over the energy supplier or the operating technology of the customer). By default, all pulse inputs (maximum 16 per component) are debounced with 15 ms (longer or shorter debounce times are possible); the period signals are 500 ms (usual period signal lengths are 1 to 9 seconds) and the Tarifum switch signals in the second range debounced.